Composite column for precast concrete structures



Oct. 18, 1966 R. K. JACOBSEN 3,279,135

COMPOSITE COLUMN FOR PRECAST CONCRETE STRUCTURES Filed Jan. 25, 1965' 4 Sheets-Sheet 1 FIE--3- I NVEN TOR.

" F I Erl RAYMOND k. JACOBSEN ATTORNEYS Oct. 18, 1966 R. K. JACOBSEN COMPOSITE COLUMN FOR PREGAST CONCRETE STRUCTURES Filed Jan. 25. 1963 4 Sheets-Sheet 2 L 7 I .I I .I m n. 1 n a... EH51 l I n I z INVENTOR. RA YMO/VD K. JA C 055 E N BY awn, 2

A T TURME Y5 FIE--5 Oct. 18, 1966 K. JACOBSEN COMPOSITE COLUMN FOR PREGAST CONCRETE STRUCTURES Filed Jan. 25, 1963 4 Sheets-Sheet 5 INVENTOR. RA YMOND K. JACOBSEN ATTORNE Y5 Oct. 18, 1966 R. K- JACOBSEN 3,279,135

COMPOSITE COLUMN FOR PRECAST CONCRETE STRUCTURES Filed Jan. 23, 1965 4 Sheets-Sheet 4 FIE--lEJ INVENTOR. RAYMOND K. JACOBSEN ,E'Mq

ATTORNE Y5 United States Patent 3,279,135 COMPOSITE COLUMN FOR PRECAST CONCRETE STRUCTURES Raymond K. Jacobsen, 1290 Bay Laurel Drive, Menlo Park, Calif. Filed Jan. 23, 1963, Ser. No. 253,425 6 Claims. (Cl. 52-127) This invention relates to a unique building construction composed of prefabricated or precast structural units of formable material such as concrete. It also relates to novel connector means particularly adapted for use with such structural units to secure them together in erecting a building.

In the building industry a form of construction, commonly referred to as the tilt-up wall method, has become quite widely known and practiced. In general the method consists of forming slabs or panels of reinforced concrete in horizontal forms and then tilting the slabs upward on edge to the vertical position to form the building wall. In the tilt-up wall structures heretofore used the slabs or panels when raised were aligned and spaced apart at the ends to form a gap between adjacent slabs. A form was then placed around the vertical edges of the spaced apart sla'bs or panels, and suitable reinforcing bars were installed so that they projected from the panels into the area that was later filled by a column of concrete poured into the forms. In this manner a column was formed embracing the two adjacent panels and interlocking the whole wall. These columns, spaced apart along the wall between the precast slabs or panels were necessary not only to interlock them together but also to provide the necessary support for the roof or additional upper floors of the building. However, in the prior art construction just described, the method of interlocking the panels and of forming the separate permanent column structures after the panels were in place had many inherent disadvantages, not the least of which was the matter of cost due to the extra material and labor required to form the columns.

In light of the foregoing, it is one principal object of my invention to provide an improved prefabricated reinforced concrete building construction formed from a series of precast panel or slab members that, when erected and connected together, form a continuous building wall having equivalent column strength at spaced apart intervals along the wall without requiring a separate column construction between wall sections.

Another object of the invention is to provide an unusually strong tilt-up wall construction using precast slab or panel members that are secured together in a predetermined partially overlapped position at their ends, said overlapped portions together providing additional columnar strength to the wall and also providing at least the minimum structural requirements for reinforced concrete columns as established under the Uniform Building Code.

Another object of the present invention is to provide a building wall structure formed from a series of precast reinforced concrete panels or slabs that can be erected easily and rapidly in a minimum of time and with a substantially reduced requirement for labor and material compared with prefabricated building constructions heretofore devised.

Still another object of the invention is to provide improved precast reinforced concrete wall panels or slab members having connection devices that can secure adjoining precast slab members to each other with great strength and rigidity in a building construction and which, if necessary, can be readily disconnected.

A further object of my invention is to provide precast concrete building panels with embedded connection de- ICC vices that are well anchored, easy to install and also easy to connect together with mating devices in adjacent panels with a minimum of labor and without need for special tools.

My invention provides a substantial advance in the building field and particularly in building methods employing tilt-up walls because it eliminates the need to construct the additional forms heretofore required in forming separate columns of concrete between panels or to provide other structural members as columns. The present invention thus provides not only a saving in material but it also enables a substantial reduction in the time required for erecting a building, because once the walls are tilted up into position and quickly connected, the roof can be readily attached and interior work can proceed at a rapid rate.

Another advantage that is afforded by my invention is that the connectable overlapping prefabricated panels that form the building walls can be removed and replaced when necessary. This gives a unique flexibility to the building design since walls can be readily disconnected and moved to expand the building size or to alter its shape as conditions dictate.

Other objects, advantages and features of my invention will become apparent from the following detailed description presented in accordance with 35 U.S.C. 112.

In the drawings:

FIG. 1 is a view in perspective of a building having a tilt-up wall construction in accordance with the principles of the present invention;

FIG. 2 is an enlarged plan view showing a pair of forms for molding precast building panels to be used in forming building walls such as shown in FIG. 1;

FIG. 3 is an enlarged fragmentary plan view of a portion of the building wall construction of FIG. 1, showing the corner connection of a pair of precast panels or slabs;

FIG. 4 is a greatly enlarged fragmentary plan view in section taken along line 44 of FIG. 5 and showing an overlapping joint of two adjoining precast concrete panels connected in accordance with the invention;

FIG. 5 is an enlarged view in elevation and in section of the adjoining precast concrete panels shown in FIG. 4 and taken along line 55 thereof;

FIG. 6 is an exploded view in perspective showing the connecting members of the precast slabs of FIGS. 4 and 5 in the disconnected position;

FIG. 7 is an enlarged fragmentary plan view showing the connector device of FIGS. 4-6 in position within a slab form before the concrete is poured;

FIG. 8 is a fragmentary view in elevation and in section taken along the line 8-8 of FIG. 7;

FIG. 9 is an enlarged fragmentary plan view in section of a pair of adjoining overlapping precast concrete slabs having a modified form of connect-or device;

FIG. 10 is an exploded view in perspective and partially in section of the connector device of FIG. 9.

With reference now to the drawings, FIG. 1 shows a building 20 being constructed with walls formed from precast concrete panels or slabs 21 embodying the principles of the invention. Although the building 20 as shown has a simple rectangular shape, it will be apparent from the following description that innumerable building floor plan shapes and sizes can be formed using my invention and also that the invention is not limited to one story structures.

It may be noted that the building 20 does not have the conventional spaced apart columns along its walls but, in accordance with the invention, the precast panels or slabs 2 1 are substantially aligned on edge and they overlap each other a predetermined amount at their vertical end edge portions. The increased wall thickness that occurs at the panel end portions which overlap, indicated generally by the numeral 22, provides a wall section of increased strength that is substantially equivalent to the strength afforded by separate columns spaced apart along the building walls as in tilt-up wall type buildings heretofore constructed, but without the many aforementioned disadvantages of such constructions. At the overlapping joint the adjoining precast reinforced concrete slabs or panels 21 are firmly connected together by a series of connection devices 23 which are embedded in the precast slabs or panels at the time they are formed.

It may be assumed that any building constructed with my tilt-up precast panels will be provided with adequate footings or any suitable foundation structure. Preferably, such foundation members would be located substantially beneath the areas 22 where the tilt-up panels or slabs 21 overlap each other along the building Wall. Similarly the loads of additional floors or roof structures would preferably be taken up to a greater degree in the areas 22 of overlapping precast wall panels 21 since these connected overlapping end portions of the slabs serve the function of columns.

The building panels or slabs 21 may all have a generally rectangular shape, although where certain sections of a building wall are to have doors or windows, the slabs can be provided with openings of the appropriate size and shape. To simplify the description of the panel structure only panels without openings will be described. In FIG. 2 is shown a plan view of a pair of forms 24 and 25 for making a pair of adjoining reinforced concrete precast panels 21a and 21b in accordance with the invention. The forms generally are of the conventional type and are arranged horizontally with frame members 26 that define the overall shape of the slab being made. Extended between the frame members 26 are a plurality of steel reinforcing bars 27 which are arranged generally parallel to each other at spaced apart intervals across the forms and similar bars 28 spaced apart and at right angles thereto. When embedded in the concrete that is poured into the forms, the bars 27 provide additional internal strength in the well known manner. Within the forms 24 and 25 are fixed the connection devices 23 that enable adjoining slabs 21 to be connected together in overlapping engagement when the building wall is constructed. The connection devices 23 are fixed at predetermined spaced apart locations within the forms so that they will be exactly aligned with mating portions of the connection devices on the adjoining slab. To firmly anchor the connection devices 23 within each slab or panel 2 1 they are not only embedded in the concrete as it is poured into the panel form, but they are originally positioned within the form so as to be retained by portions of the embedded steel reinforcing rods 27. After the slab forms 24 and 25 have been filled with concrete and smoothed off on the top the connection devices 23 are precisely located within the slab or panel and completely flush with its outer surfaces.

The connector devices 23 which hold the overlapped slabs or panels together in a building construction are an important part of my invention and one form thereof is shown in detail in FIGS. 48. Since the connection devices perform the function of structurally tying the adjoining overlapping panels together where their end surfaces engage in substantially flush contact, each connection device must provide a bridging or tie member extending between the panels and also means within each adjoining panel to retain an end of the tie member. In addition, the connector devices within both adjoining slabs must be positioned so as to be aligned when the slabs are moved into position as a building is erected.

Thus the connection device 23 comprises essentially a pair of first and second mating members 29 and 30 respectively that are embedded in adjoining slabs or panels for holding the opposite ends of a tie member 31 extending between the members. In FIG. 4, the members 2931 are shown holding the overlapped end portions 22 of a pair of tilt-up wall slabs or panels 21a and 21b together. The male or first member 29 of the connector 23 comprises an elongated sheet metal enclosure 32 fixed within the slab 21a and having an open end 33 that is flush with the surface 34 of the slab 21a adjacent the adjoining slab 21b. Extending at right angles through the enclosure 32 is a rigid bar 35 having a cross-section giving it a substantial resistance to bending. Fixed to the opposite ends of the bar 35 are a pair of right angle members 36 and 37 each having one leg 38 fixed (as by welding) to an end of the bar 35 and with their other leg members 39 being aligned and extending parallel to the bar 35 and thus transversely to the enclosure 32. The length of the bar 35 and hence the distance between the legs 38 of the angle members 36 and 37 is such that connector member 29 can be positioned between two reinforcing rods 27 within the slab 21a so that the extended legs 39 are just in back of the rods 27, thereby firmly anchoring the bar 35 within the slab 21a. Fixed to the end of the leg 39 of the angle member 36 is a short length of another smaller angle member 40 which serves as a positioning member to hold the connector member 29 in the exact predetermined location within the form as the slab 21a is poured. As shown in FIGS. 7 and 8, the angle member 40 has an outer flange 41 that is adapted to bear against a frame member 26 of the slab form 24 when the slab is poured and it is thus flush with the end surface 42 of the solidified slab or panel 21a.

The tie member 31 or connecting link between the members 29 and 30 consists of an elongated ring having a generally rectangular central opening 43 (FIG. 5) through which passes the bar 35. There is ample clearance between the opening 43 and the bar 35 so that link 31 can readily be moved from a completely retracted position within the enclosure 32 and beneath the surface 34 of the slab 21a to an extended position wherein the link 31 and its central opening 43 projects beyond the slab surface and into the mating connection member 30. The amount of extension of the link 31 is, of course, limited by the bar 35. At the rear end of the elongated enclosure 32 is a tubular member 44 providing an opening which enables the tie member or link 31 to be engaged from the outer side 45 of the slab 21a so that it can be pushed to the extended position when adjoining slabs are ready to be connected.

The mating female or second connector member 30 comprises an elongated sheet metal enclosure 48 that is embedded in the adjoining slab 21b in a position substantially parallel with the plane of the slab and thus transverse to the position of the enclosure 32 in the slab 21a. The enclosure 48 is essentially channel-shaped with its long open side 49 located flush with the inside surface 50 of the slab or panel section 21b that engages the surface 34 of the adjoining overlapping slab section 21a. One end 51 of the channel-shaped enclosure within the slab 21b is covered and the opposite end 52 is also open and flush with the end surface 53 of the slab 2112. A short angle member 54 is fixed to the enclosure 48 near its open end 52 and serves to position the connector member 30 properly with its slab form 25 in the same manner as the positioning member 40 on the male connector member 29. Fixed transversely to the top and bottom sides of the enclosure'48 and extending rearwardly therefrom through the slab 21b are a pair of rigid metal plates 55 of substantial thickness, and welded to the ends of both plates 55 are a pair of short transverse members 56 of steel reinforcing bar. These members 56 are positioned on the plates 55 so that they are located just in back of a pair of the reinforcing rods 27b extending through the slab 21b when the open front 49 of the enclosure member 48 is properly flush with the engaging surface 50 of the slab 21b. Thus when the member 30 is fixed within the slab 21b it is structurally anchored by the bars 55 behind the buried reinforcing bars 27b.

Across the open front 49 of the enclosure 48 are fixed a pair of rigid plates 57 that are spaced apart so as to form a gap 58 that is aligned with the open end 33 of the enclosure 32 of the adjoining slab 21a containing the movable tie member 31. The plates 57 are also partially connected to the aforementioned rearwardly extending rigid plate members 55 that are restrained by the bars 56 behind the reinforcing rods 27b within the slab.

To secure the connection between the members 29 and 30 and thus the slabs 21a and 21b, a rigid wedgeshaped pin member 60 is adapted to be inserted through the end opening 52 afforded by the enclosure 48 at the end of the slab 21b and through the elongated opening 43 of the tie member or link 31 after it has been extended from its enclosure 32 through the gap 58 between the plates 57 and into the enclosure 48 of the slab 21b. As the pin 60 is inserted through the tie member 31 one of its sides 61 bears against the plates 57. Further insertion of the pin 60 causes the tie member to extend to its limit and pull up tightly on the bar 35. Ultimately, the pin 60 itself Wedges tightly within the link opening 43 while bearing against the plates 57. Thus, as the tapered pin is inserted properly it pulls the tie member father into the enclosure 48 and thereby pulls the adjoining slabs 21a and 21b tightly together into flush engagement in a firmly locked joint. As shown in FIG. 4, strips of some compressible material 62 such as a rubber composition material may be placed between the slabs before they are pulled close together thereby providing a tight moisture-proof seal between them. No mortaring of the joint is required. When the pin 60 is properly in place within the tie member 31 it is fully within the enclosure 48 and thus the slab member 21b. Should the slab members 21a and 21b ever need to be disconnected during a dismantling or remodeling of the building, each pin 60 is provided with a hole 63 at one end so that it can be readily grasped for quick removal. Mere removal of the pins 60 is all that is required to completely disconnect the linking structural tie between two connected panel members such as the slabs 21a and 21b.

An alternate form of connection device 65 which may be used with the unique building construction of the present invention is shown in FIGS. 9 and and comprises generally a pair of embedded connector members 66 and 67 with a heavy machine bolt 68 forming the connecting link. The first member 66 consists simply of a short box-like hollow section 69 having an open end 70 adapted to be flush with the inner surface 71 of one slab member 210. The section 69 may be formed simply from two angle members of the same length that are welded together. Attached transversely to the inner end of the section 69 is a relatively short rigid member 72 which is adapted to fit behind a pair of parallel reinforcing rods 73 within the slab before the concrete is poured around the member 66. Within the hollow section 69 and transverse to its longitudinal axis is secured a fixed nut member 74 having a central threaded opening 75.

The complementary connector 67 of the connector device 65 consists of a rigid piece of relatively thick metal retaining plate 76 having a central opening 77 with aligned enclosure portions 78 and 79 such as metal pipe sections extending perpendicular from opposite sides of the plate 76 and concentric with the central opening 77. In the slab member 21d as shown in FIG. 9, the connector member 67 is positioned with its open forward end 80 flush with the surface 81 of the slab adjacent the adjoining slab 21c and with the end portions of the plate 76 located behind a pair of reinforcing rods 82 within the slab 21d. If preferred, extensions with end members similar to the angle members 40 and 54 could be attached to the members 72 and 76 to hold in position the connector members 66 and 67 within their slab forms when the slabs 21c and 21d are being made.

The large sized bolt 68 which is the connecting link for the device 65 is inserted from the rear of the slab 2111 when it is in the proper predetermined position relative to the adjoining slab 21c with the opening 77 in the plate 76 substantially aligned with the section 69 and its fixed nut 74. The bolt 68 is then taken up to its maximum tension with its head 83 bearing on the plate 76. The plate opening 77 is made fairly large so that its alignment with the connector member 69 and its fixed nut member 74 is not critical.

As apparent in FIGS. 4 and 9 showing the two forms of connectors in a horizontal cross section of a wall constructed according to my invention, the overlapped porations 22 of each pair of adjoining wall section 21 become as a single column unit when connected. This column 22 fulfills all of the requirements of the Uniform Building Code for reinforced concrete columns, including the minimum cross sectional column dimensions, the number of steel reinforcing forms (four) extending vertically within the column, and the required internal transverse members which are provided by the bars such as members 56 that anchor the connector means.

In constructing a building using the precast concrete panels or slabs as described above, the method varies from that previously employed with other prefabricated building constructions. On the building site a suitable foundation consisting of a floating type slab or piers and footings is constructed. The panels or wall slabs can then be formed as in the forms 24 and 25 at the site in the aforesaid manner as shown in FIG. 2. When the slabs 21 have solidified they are removed from their forms and raised into their upright position. A first slab is placed into alignment with the wall line of the building and then an adjoining slab is moved into an overlapping position relative to the first slab with the connector members of both slabs being in alignment. The connection devices 23 or 65 are then connected together to secure the overlapping joint. Additional slabs or panels of the building wall are then added in the same manner.

At the corners of the building 20, as shown in FIGS. 1 and 3, the adjoining panels or slabs 21 are connected by a series of right angle corner members 85 which are bolted to angle members 86 that are anchored to the ends of the panels 21. Other suitable corner connection means (not shown) could also be used within the scope of the invention.

From the foregoing it should be apparent that the present invention is a unique tilt-up wall construction with many advantages over prior art constructions. The precast concrete panels or slabs can be formed rapidly with a minimum of labor and material and can then be tilted up or lifted into position and easily joined with other similar panels or slabs to form a building wall. A vast amount of time and labor can be saved and the resulting structure is strong, durable, yet attractive and also capable of being disassembled or dismantled later on for remodeling, or expansion with the slabs.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. A building wall construction comprising a plurality of precast reinforced concrete wall panels, said panels being supported on edge in an upright position to form the walls of a building:

said wall sections being overlapped vertically with portions of their ends in flatwise engagement, thereby forming a series of spaced apart column-like portions along the building wall having double panel thickness; and connection means for holding said adjoining wall panels together at their overlapped ends, each said means including a linking member retained completely within one of said panels and extendable outwardly therefrom substantially perpendicular to the plane of the adjoining panel, a separate connector member embedded in the said adjoining panel having means forming a recess aligned with and adapted to receive one end of said linking member, said recess providing access to said linking member from an exposed surface of said adjoining panel when said panels are connected, and means for engaging said linking member at its other end to anchor it in said recess and retain said adjoining panels closer together.

2. A wall construction for buildings comprising:

a plurality of precast reinforced concrete wall sections, said sections being supported on edge in an upright position with the end portion of adjacent sections being overlapped, said overlapped end portions thereby forming spaced apart portions of increased thickness along the wall that serve as column supports for the building walls and roof;

a plurality of spaced apart parallel reinforcing bars embedded in each of said sections;

first and second connector means secured to said reinforcing bars within the adjacent end portions of adjoining Wall sections, said first connector means in one wall section including means forming a cavity within the wall section, a rigid retaining member embedded within the wall section and extending transversely through said cavity, said retaining member having extended end portions engaging a pair of said reinforcing bars;

a movable link within said cavity, said link having an elongated central opening and fitting loosely around said retaining member, said link being extendable outwardly from said cavity so that a portion of its central opening project beyond the surface of the wall section, the amount of its projection being limited by said transverse retaining member;

said second connector means in the adjoining wall section including means forming a cavity accessible from the end surface of the Wall section, bearing plates across the front of said cavity forming a gap for receiving said movable link when it is extended from the adjoining wall section, means extending inwardly from said bearing plate and located behind a pair of said reinforcing bars within said wall section for anchoring said plates and the cavity forming means within the wall section;

and tapered pin means adapted to be inserted from the end of said second wall section into its said cavity and through the opening in said link, said pin means engaging said bearing plates on one of its sides;

whereby as it is inserted, the pin means pulls the movable link against the retaining member and forces the adjoining wall sections closer together While forming a firmly locked joint.

3. A wall construction for buildings comprising:

a plurality 'of precast reinforced concrete wall sections, said sections being supported on edge in an upright position with the end portions of adjacent sections being overlapped, said overlapped end portions thereby forming spaced apart portions of increased thickness along the Wall that serve as column supports for the building Walls and roof;

a plurality of spaced apart parallel reinforcing bars embedded in each of said sections;

first and second connector means embedded Within the adjacent end portions of adjoining wall sections and connected to said bars, said first connector means in one wall section including means forming a cavity within the wall section, a rigid retaining member extending transversely through said cavity;

an elongated movable link extending axially within said cavity, said link having an elongated central opening through which extend said retaining member, said link being extendable outwardly from said cavity beyond the surface of the wall section, the amount of its projection being limited by said transverse retaining member;

said second connector means in the adjoining wall section including means forming a cavity accessible from the end surface of the wall section, bearing members across the front of said cavity forming a gap for receiving said movable link when it is extended from the adjoining wall section;

and Wedge shaped means adapted to be inserted from the end of said second Wall section into its said cavity and through the opening in said link, said latter means engaging said bearing member on one of its sides;

whereby, as said Wedge shaped member is inserted, it pulls the adjoining wall sections closer together and forms a firmly locked joint.

4. A wall construction for buildings comprising:

a plurality of precast reinforced concrete Wall sections, said sections being supported on edge in an upright position with the end portions of adjacent sections being overlapped, said overlapped end portions thereby forming spaced apart portions of increased thickness along the wall that serve as column supports for the building walls and roof;

a plurality of spaced apart parallel reinforcing bars embedded in each of said sections;

first and second connector means secured to said reinforcing bars Within the said end portions of the adjoining wall sections, said first connector means including means forming a cavity Within the wall section, a rigid retaining member extending transversely through said cavity, means on said retaining member for anchoring it within said wall section behind a pair of said reinforcing bars;

a movable link within said cavity, said link having an elongated central opening and adapted to fit loosely around said retaining member, said link being extenda=ble outwardly from said cavity so that a portion of its central opening projects beyond the surface of the Wall section, the amount of its projection being limited by said transverse retaining member, means providing access to said cavity from the outside surface of said wall section for pushing said link to the extended position;

said second connector means in the adjoining wall section including means forming a cavity that is accessible from the end surface of the wall section, bearing plates across the front of said latter cavity forming a gap for receiving said movable link when it is extended from the adjoining wall section, means extending inwardly from said bearing plate and located behind a pair of said reinforcing bars in said Wall section for anchoring said plates and the cavity forming means within the wall section;

and tapered pin means adapted to be inserted from the end of said second wall section into its said cavity and through the opening in said pin, said pin means engaging said bearing plates on one of its sides;

whereby as the pin means is inserted, it pulls the adjoining wall sections closer together and forms a firmly locked connection between them.

5. A wall construction for buildings comprising:

a plurality of precast reinforced concrete wall sections, said sections being supported on edge in an upright position with the end portions of adjacent sections being overlapped a predetermined amount, each pair of said overlapped end portions thereby forming a column-like portion of increased thickness that serves alotgg the wall to support the building walls and roo a plurality of spaced apart parallel reinforcing bars embedded in each of said sections, at least two of said reinforcing bars extending longitudinally within each of said overlapped end portions;

a plurality of male and female connector means secured to said reinforcing bars at spaced apart intervals within the adjacent overlapping end portions of adjoining wall section, each said male connector means in one wall section including means forming a cavity within the wall section, a rigid retaining member extending transversely through said cavity and having end portions embedded in the surrounding wall section;

an elongated movable link extending axially within said cavity, said link having an elongated central opening through which extends said retaining member, said link being extendable outwardly from said cavity beyond the surface of the wall section, the amount of its projection being limited by said transverse retaining member;

each said female connector means in the adjoining wall section including means forming a cavity accessible from the end surface of the Wall section, bearing members across the front of said latter cavity forming a gap for receiving said movable link when it is extended from the adjoining wall section;

and wedge shaped means adapted to be inserted from the end of the wall section into said latter cavity and through the opening in said link, said latter means engaging said bearing member on one of its sides;

whereby as said wedge shaped member is inserted it pulls the adjoining wall sections closer together and forms a firmly locked joint.

6. A wall construction for buildings comprising:

a plurality of precast reinforced concrete wall sections, said sections being supported on edge in an upright position with the end portions of adjacent sections being overlapped, each pair of said over apped end portions thereby forming a column-like portion of increased thickness that serves along the wall to support the building Walls and roof;

a plurality of spaced apart parallel reinforcing bars embedded in each of said sections, at least two of said reinforcing bars extending longitudinally and vertically within each of said overlapped end portions;

a plurality of male and female connector means secured to said reinforcing bars at vertically spaced apart intervals Within the said overlapping end portions of the adjoining wall sections, said male connector means being aligned with said female connector means when said adjoining wall sections are overlapped a predetermined amount;

means controllable from the end of one of said overlapped wall sections for mechanically interconnecting each aligned pair of said male and female connector means.

References Cited by the Examiner UNITED STATES PATENTS 1,079,111 11/ 1913 Conzelman 52429 1,461,452 7/ 1923 Pritchard 52489 1,462,622 7/1923 Phelan 52-584 2,129,369 9/1938 Faber 52-609 2,229,779 1/1941 Thomas 52583 2,664,740 1/ 1954 Cochrane 52.583 2,920,475 1/ 1960 Graham 52-432 FOREIGN PATENTS 219,245 12/ 195 8 Australia. 576,917 4/ 1946 Great Britain.

FRANK L. ABBOTT, Primary Examiner.

HENRY C. SUTHERLAND, Examiner.

I. L. RIDGILL, Assistant Examiner. 

4. A WALL CONSTRUCTION FOR BUILDING COMPRSING: A PLURALITY OF PRECAST REINFORCED CONCRETE WALL SECTIONS; SAID SECTIONS BEING SUPPORTED ON EDGE IN AN UPRIGHT POSITION WITH THE END PORTIONS THEREBEING OVERLAPPED, SAID OVERLAPPED END PORTIONS THEREBY FORMING SPACED APART PORTIONS OF INCREASED THICKNESS ALONG THE WALL THAT SERVE AS COLUMN SUPPORTS FOR THE BUILDING WALLS AND ROOF; A PLURALITY OF SPACED APART PARALLEL REINFORCING BARS EMBEDDED IN EACH OF SAID SECTIONS; FIRST AND SECOND CONNECTOR MEANS SECURED TO SAID REINFORCING BARS WITHIN THE SAID END PORTIONS OF THE ADJOINING WALLS SECTIONS, SAID FIRST CONNECTOR MEANS INCLUDING MEANS FORMING A CAVITY WITHIN THE WALL SECTION, A RIGID RETAINING MEMBER EXTENDING TRANSVERSELY THROUGH SAID CAVITY, MEANS ON SAID RETAINING MEMBER FOR ANCHOR IT WITHIN SAID WALL SECTION BEHIND A PAIR OF SAID REINFORCING BARS; A MOVABLE LINK WITHIN SAID CAVITY, SAID LINK HAVING AN ELONGATED CENTRAL OPENING AND ADAPTED TO FIT LOOSELY AROUND SAID RETAINING MEMBER, SAID LINK BEING EXTENDABLE OUTWARDLY FROM SAID CAVITY SO THAT A PORTION OF ITS CENTRAL OPENING PROJECTS BEYOND THE SURFACE OF THE WALL SECTION, THE AMOUNT OF ITS PROJECTION BEING LIMITED BY SAID TRANSVERSE RETAINING MEMBER, MEANS PROVIDING ACCESS TO SAID CAVITY FROM THE OUTSIDE SURFACE OF SAID WALL SECTION FOR PUSHING SAID LINK TO THE EXTENDED POSITION; 